Obot versions up to 0.22.1 with authentication enabled are vulnerable to an OAuth dynamic client registration flaw that allows an attacker to steal API tokens via audience confusion. An unauthenticated attacker can register an OAuth client with an arbitrary redirect URI, and the authorization flow auto-completes without user consent. If a logged-in user visits a crafted authorization URL, the attacker receives an authorization code that can be exchanged for an access token carrying the victim's full group permissions. This token can be used against API endpoints the victim is authorized for, enabling unauthorized access until token revocation. The vulnerability is fixed in version 0.23.0 with added consent screens, token audience restrictions, and validation.